We’re being asked to determine the equilibrium pressure of N_{2} given the following equilibrium reaction:

**2NO (g) ⇌ N _{2} (g) + O_{2} (g)**

**When dealing with equilibrium and K _{c}:**

• **K _{p} **→ equilibrium units are in atm

•

$\overline{){\mathbf{Kp}}{\mathbf{=}}\frac{\mathbf{products}}{\mathbf{reactants}}}$

▪ **only aqueous and gaseous species** are included in the equilibrium expression

▪ the **coefficient** of each compound in the reaction equation will be the **exponent **of the pressure in the equilibrium expression

**Given: **

**Initial pressure:**

NO = 26.1 atm

At 200 °C, the equilibrium constant (K_{p}) for the reaction below is 2.44 x 10^{3.}

2NO (g) ⇌ N_{2} (g) + O_{2} (g)

A closed vessel is charged with 26.1 atm of NO. What is the partial pressure of N_{2} at equilibrium?

a. 0.726 atm

b. 3.21 atm

c. 12.92 atm

d. 2.88 atm

e. 18.16 atm